Synthesis and properties of novel poly(aryl ether ketone)s containing both diphenyl moiety and amide linkages in the main chains

New monomers, 4,4′-bis(4-phenoxybenzoyl)diphenyl (BPOBDP) and N,N′-bis(4-phenoxybenzoyl)-p-phenylenediamine (BPBPPD), were conveniently synthesized via simple synthetic procedures from readily available materials. A series of novel poly(aryl ether ketone)s containing both diphenyl moiety and amide linkages in the main chains were prepared by electrophilic Friedel–Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBDP and BPBPPD, over a wide range of BPOBDP/BPBPPD molar ratios, in the presence of anhydrous AlCl3 and N-methylpyrrolidone (NMP) in 1,2-dichloroethane (DCE). All the polymers are semicrystalline and had remarkably increased Tgs over commercially available PEEK and PEKK due to the incorporation of the diphenyl moiety and amide linkages in the main chains. The polymers with 40–60 mol% BPBPPD had not only high Tgs of 183–189 °C, but also moderate Tms of 314–328 °C, which are very suitable for the melt processing. These polymers had tensile strengths of 107.4–111.5 MPa, Youngʹs moduli of 2.20–2.45 GPa, and elongations at break of 11.3–13.5% and exhibited high thermal stability and good resistance to organic solvents.